Freeze dried extracts of Bidens biternata (Lour.) Merr. and Sheriff. show significant antidiarrheal activity in in-vivo models of diarrhea

Ethnopharmacological relevance of the study

Diarrhea remains one of the main killers of children aged below five years. Traditional antidiarrheal remedies form a potentially viable source of novel low cost efficacious treatments in low resource settings. There is therefore a pressing need to scientifically evaluate these remedies.

Aim of the study

This study aimed to investigate the in vivo and in vitro antidiarrheal activity of freeze dried Bidens biternata, a herb used in traditional Ayurvedic medicine in the management of diarrhea.

Materials and methods

In the castor oil test, twenty (20) adult Sprague-Dawley rats were randomized to a negative control (normal saline, n=5), a positive control (5 mg/kg loperamide, n=5), and two test groups. The low dose test group received 200 mg/kg Bidens biternata extract (n=5) while the high dose test group received 400 mg/kg B. biternata extract (n=5). Castor oil (4 ml/kg) was then administered to the animals one hour after administration of the respective treatments after which the total mass of fecal output excreted after four (4) hours was determined.

In the charcoal meal test fifteen (15) Sprague Dawley rats were randomized to a control group (normal saline 5 ml/kg orally, n=5), a positive control group (atropine sulfate 0.1 mg/kg i.p., n=5) and a test group (400 mg/kg B. biternata extract, n=5). Charcoal meal was then administered via oral gavage to each rat thirty (30) minutes after the administration of the various treatments. The distance covered by the charcoal meal from the pylorus was then determined after sacrifice of the animals thirty minutes after the meal.

In the enteropooling test twenty (20) Sprague-Dawley rats were randomized to a control group (5% v/v ethanol in normal saline, n=5), a positive control group (5 mg/kg loperamide, n=5) and a test group (400 mg/kg B. biternata extract, n=5). For each group prostaglandin E2 (PGE2) (100 μg/kg) was administered immediately after the treatments. The animals were then sacrificed half an hour later and the volume of the small intestine contents determined.

The effects of different concentrations of B. biternata extract (0.5. 1.0, 2.0, 3.0 and 5.0 mg/ml) on jejunal contraction were investigated and a dose-response curve constructed using the experimental data after which The ED50 dose was determined. The effect of tamsulosin (α1 adrenergic blocker), yohimbine (α2 adrenergic blocker), propranolol (β adrenergic blocker) and naloxone (μ opioid blocker) on the contractile activity of the extract were also investigated.

The experimental data were expressed as mean±standard error of mean (SEM) and then analyzed using one-way ANOVA followed by Tukey's post hoc test in cases of significance (set at p<0.05).